(1) The first consideration for ease and safety in erection should he to so arrange all details, joints, and connections that a structure may be connected, made self-sustaining and safe in the shortest time possible.
(2) Entering connections of any character should he avoided when possible, notably on top chords, floor beam and stringer con nections, splices in girders, etc.
(3) When practicable, joints should be so arranged as to avoid having to put members together by entering them on end, as it is often impossible to get the necessary clearance in which to do this.
(4) In all through spans floor connections should be so arranged that the floor system can be put in place after the trusses or girders have been erected in their final position, and vice versa, so that the trusses or girders can be erected after the floor system has been set in place.
(5) All lateral bracing, hitch-plates, rivets in laterals, etc., should, as far as possible, be kept clear of the bottom of the ties, it being very expensive to cut out ties to clear such obstructions.
(6) Lateral plates should be shipped loose, or bolted on, so that they do not project outside of the member, whenever there is danger of them being broken of in unloading and handling.
(7) Loose fillers should be avoided. They should be tacked on with rivets, countersunk where necessary.
(8) In elevated railroad work, viaducts, and similar struc tures, where longitudinal girders frame into exoss girders, shelf angles should be provided on the latter. In these structures the expansion joints should be so arranged that the rivets connecting the fixed span to the cross girder can be driven after the expansion span is in place.
(9) in viaducts, etc., two spans, abutting on a bent, should be so arranged that either span can be set in place entirely independent of the other. The same thing applies to girder spans of different depth resting on the same bent.
(10) Holes for anchor bolts should be so arranged that the holes in the masonry can be drilled and the bolts put in place after the structure has been erected complete. In concrete masonry they should be set very carefully according to data furnished by the Bridge Company.
(11) In structures consisting of more than one span a separate bed-plate should be provided for each shoe. This is particularly important where an old structure is to be replaced; if two shoes were put on one bed-plate or two spans connected on the same pin, it would necessitate removing two old spans in order to erect one new one.
(12) In pin-connected spans the sections of top chords nearest the center should be made with at least two pinholes. On skew spans the chord splices should be so located that two opposite panels can be erected without moving the traveler.
(13) Tie plates should be kept far enough away from the joints, and enough rivets should be countersunk inside the chord, to allow of eye bars and other members being easily set in place.
(14) Posts with channels or angles turned out and notched at the ends should, whenever possible, he avoided.
In conclusion, it may be said that the author has written this treatise with the idea of preventing the beginner from falling into the more common errors of judgment, as well as helping him to become proficient in detailing according to good common practice.